Circuit interrupter



lT SSES:

Aug. 15, 1950 Patented Aug. 15', 1,9570

CIRCUIT INTERRUPTER James M. Wallace, Braddock, Pa.,

Westinghouse Electric Corporation,

assignor to East Pittsburgh, Pa., a corporation of Pennsylvania Application June-25, 1945, Serial No. 601,389

3 Claims.

This invention relates to electric circuit interrupters in general, and especially to high-voltage fuses.

In order to economically furnish proper highvoltage fuse protection rfor distribution transformers on rural lines, it is necessary that the cost of such protection be extremely low, and consequently that the fuse structure be relatively simply constructed of few parts, and be capable of easy installation.

One object of this invention, therefore, is to provide a novel simplified form of high-voltage fuse.

Another object of this invention is to provide a novel replaceable fuse unit which includes as a part thereof means for readily connecting the unit to a line and apparatus terminal.

These and other objects of this invention will become more apparent upon consideration of the following description of a preferred embodiment thereof, when taken in connection with the attached drawing, in which:

Figure 1 is an elevational view of a transformer pole installation employing a fuse constructed in accordance with this invention;

Fig. 2 is an enlarged elevation view of the fuse shown in Fig. 1, but looking in a direction substantially at right angles to Fig. 1; and

Fig. 3 is an enlarged elevation view of the fuse shown in Fig. 1 with a part thereof in section.

The fuse comprising this invention may be regarded as including three main parts, a clamp portion 2, fuse portion 4 and tail 6. Clamp portion 2 is illustrated as being formed of two wires of resilient material, such as copper alloy or the like, but it will be obvious that, if desired, it may be formed of a single such wire. The two wires forming clamp portion 2 are separated adjacent one end and coiled inwardly towards each other to form a spring hook-eye portion 8, and these ends of the Wires are then crossed and separated slightly to form a clamp portion I for receiving a line conductor 32, with the wires then being brought together and bent-outwardly as at I2, to provide a iiared entrance to clamp portion I0. At the other side of hook-eye portion 8, the wires are brought together as at I4 to form a stop against which ends I2 of the wires may abut when the clamp is not positioned on a conductor 32. Beyond stop portion I4, the wires are again separated and each curved in the form of a semicircle and again brought together as at I8, thus forming another hook-eye portion I6 adjacent the other ends of the wires.

The portions I8 of the wires form a terminal to (Cl. 20D-115.5)

which one end of a fusible wire 20 may be attached, as for example, by soldering or the like. Fusible wire 20 may be of any well known fusible material or alloys of such materials. A strain wire 22 of a material having a higher resistance than fusible wire 20 is also adapted to be attached to terminal portion I8 of the clamp, as by soldering or the like, with the other ends of fusible wire 20 and strain wire 22 being hooked over the small end coils 24 of a normally extended tension spring. The fusible and strain wires 20 and 22, together with a part of terminal portion I8 of the clamp, are adapted to be positioned within a tube 46 of insulating material, preferably a material which is capable of evolving an arc-extinguishing gas when in proximity to an electric arc, such for example as ber or a synthetic resin. The upper end of tube 46 is provided with a cap 48 suitably secured to the tube, for example as .by the indented portion 50, and cap 48 is secured to terminal I8 of the clamp, for example as by soldering or the like. The tension spring is provided with an intermediate portion 26 having coils larger than end coils 24, and coils 24 and 26 of the spring are adapted to be positioned within tube 46 with the outer end of the spring provided with larger coils 28 adapted to engage the lower end of tube 46. In addition to wires 20 and 22 being hooked over the small coils 24 of the spring, flexible tail 6 of the fuse has its end also positioned within the coils of spring portion 24, and these are then filled with solder to securely anchor tail 6 and wires 20 and 22 to the upper end of the tension spring. The purpose of the tension spring is to rapidly move tail 6 of the fuse downwardly and away from tube 46 when fusible element 20 and strain wire 22 melt.

The fuse comprising clamp 2, fuse 4 and tail 6, comprises a replaceable unit which may be readily attached to a line conductor 32 when carrying current by lifting the unit with a hook stick or the like inserted in hook-eye 8, onto conductor 32y and then placing the hook stick in hook-eye I6 and pulling downwardly so that the conductor will enter clamp portion I0 of clamp 2 to be securely frictionally held by the clamp. Tail 6 of the fuse is made suiiiciently long so that it may be cut to the size necessary for connection to the terminal of the adjacent electrical apparatus which it is desired to protect.

The mounting illustrated in Fig. 1 comprises a pole 30 carrying line conductor 32 on a pole top insulator 34 to which the line conductor is secured as by means of a tie-wire 36. A transformer 40 is mounted on the pole in any desired manner, for

' fuse unit"des`cribed herein provides,in combina- "tion, a hot line clamp, anon-renewable eXp'ul-- 'attachment to'a'suita'ble terminal. Such' a fuse example as .by brackets 42. The pole may also sired that the invention be interpreted as broadly carry a neutra] conductor 38 at one side thereof. as possible, and that it be limited only as required Transformer 40 is provided with a bushing for a by the prior art. high-tension terminal 44 to which the tail 5 of a I claim as my invention:

fuse constructed in accordance with this invenf, 1. A fuse comprising, a line clamp formed of tion is adapted to be connected in the first step resilient strip material bent at the upper end of of connecting the transformer to the high-tenthe clamp to form a downwardly opening outsion conductor 3 2. The fuse mayfther'l be lifted on ""w'ardly *flared "line cfonduc'tor receiving and to conductor 32 and then drawn down into clampclamping portion, said strip material bent intering engagement therewith in the manner de- 10 mediate its ends to form a hook-eye located scribed above. Y intermediate the ends of the clamp and which is In response to the flow of currents in the cirvclosedV at least on its lower side so that a hookcuit above a predetermined Value, fuse element stick; maybe inserted in said hook-eye to pull 20 Will melt in the 11511211'Wayfvaridfstlairi'WiieZZ 4 saidclamp'fdowwardly onto a line conductor,

will likewise be immediately consumed so that l5 the other end of Asaid strip material at the other the tension spring within tube 46vwi1l be free to end of the clamp having fusible means directly withdraw tail 6 from the tubea'ssisted, ofcourse, f and :permanently secured to an integral part by the expulsion action of eases developed within thereof, and e flexible terminal conductor supt"he tube, and ibY gIeYY- BIOWllg 0f t"he fuse ported solely by said fusible means. thUiS .IfeSUltS in pltetilg the tIaIlSfOlmeI l105 20 2. A fuse renewable in its entirety, comprising, 'disconnecting'it from its high-tensionsource of a, line' 15mn 'fug'i'l 'meting hvmg aidreCt-perelectrical 'energyfand in" addition, provides" 'an maiient'conneetibr'tvith' 'an integral 'partei-seid air gap in the CI'Cllt between Clamp 2 and telsclamp, and flexible conducting means directly "former terminal" 44- Afier the' fils@ 'is blown. and permanently secured tes'eidiusible ineens, olainp" 2 may be removed'irom oondu'otor`32 by 25 so that said' clmp'part endeondiietinenie'ens inserting a ho'okfstick in'hook-eyeg' ioinove comprise 'terminale for 'the-ere formedup'on the' clampupwardly and' oi'line conductor" 32. "fusion of Safd'fugi'le means clamp zmey then lbediecarded, togetherwith s.' Afuee' edfii'p'rising, yeilineeleimp,l aiiexible the remains Vof'tail 6,' and a nwiuse unit' C'ointerminal conducted fd'e'itle4 nieeiisreenneeted -priemg- *elempf 2, fuse' 4 and teil s'be'ineeited intim place' in 'the manner described.

` From the foregoing, 'it is apparent that 'the between said clamp and conductor' by 'direct 'and permanent connections" with ari iite'g'ral 'part of said clamp andl said'conductorjrespectively, s'aid clamp including a downwardly opening 'spring clamp portion'Y dfor`fengaging a' "Iine' 'condiicton av hookLe'ye'above said' clamp"prtion, 'and'` a lokeye lcatd intermediateSd'lllp portion and said 'fusible' means, 'said' ho'okeye' located below said clanfl'ping Yportion being "closed 'at' 'least on "its'lower side so vthat a"hook"sticl{'iil`ay'be sion fuse element and a'iiexible conductor'for' 35 has the obvious advantage'thatbeing constructed of'jfew parts, it isextremely cheap 'and'sim'ple to build, as" well as being'simp'le to" 'install a'nd'operate, and yet meets the necessary requirements' ofi'nw' 'positive' air' gap' isolation'of the circuit from "the kinserted therein td pullee'idtlaine downwardly f. onto aconductor.

'faulted transformer Or'circult protectedthereby, l vtogether with 'providing a 'suitable 'indication' of i operation. In4 addition, this fl'lse possesses'the 'i EFERNCES '(IIEDk V`further 'advantage that it'does r'l'ot'require 'addi- 45 tional insmationtdbe placed inthe distribution ,ilggargenferens'aremof 'record 'm the circuit, with the attendant increase ir'rposs'ibility 4vof failure' of such insulation. The'fse employs UN'ITED'STATES PATENTS j Aonly the'in's'ulation Vwhich'isnecessary4 forthe "Number Name fijate distributioncircuit itself, andg'thereforeyhas Ano'f'il 1;'6531'252 Hepbick 'Meir` "20I '1928 tendency 'to reduce'the insulation level 'of 'the 1,322,333 Chandler ^'Sep1 '15,"1931 v"line Y Y i j 2,198,341 Pit't'iiiarlet el. Aprso; i940 Having 'described apreferred embodiment'of 2,270,225 Stjrayer Jan; 13,194?J fthel invention 'in accordance with thel patent 2,233,630 Charialer July 7; 1942 statutes, it is desired that-the jin'ventionbe 'not if.; "2291035 Tman S'ep1j"29; 19 limited'to this particularembodirnent inasmuch 21323)'177 St'r'n'h'ayr Agfgl; 1943 as it will be' obvious, particularly vvtopersons skilled in the art, that many changes andfmodi- FQREIQN PATENTS fications may =be made in this specic'fstructure Number y y' Country Date `without departing from the broad 'spirit andfo A"358,944 "Great"Britain Oct.' 15-, 1931 *scope of this invention. v'lilccordinglyitfis de- 

